Problem reading gear position on AIM dash

[ghickman]

Hi All
Getting set to go testing or FB next week and encountered a problem with our AIM Mychron XG Log reading the gear position potentiometer.

The problem we're having is neutral and 6th gear are giving the same relative value. This causes the Neutral position and 6th gear position on the dash to read a 0 as if it's in neutral when in 6th gear.

Talked with the techs at AIM and they're puzzled. They had me go into the diagnostics and read the Mvolts coming out of the gear position potentiometer and it reads the same for neutral and 6th.

Anyone able to shed some light on this problem?? I really don't want to do the calculated gear position which involves an algorithym using wheel speed and engine
rpm.

FYI- this is a GSXR1000 motor

HELP

Gary Hickman

[Daryl DeArman]

A suggestion: Try disconnecting the pot from the shift lever and move it through its' range...does the pot give the same mV out reading at any two spots within its' range? If so, the pot is bad. If not, the pot is either moving or the linkage is such that the pot is in the same spot when the trans is in 6th and N.

[Matt Conrad]

Gary,

George Dean always provides us with a gear position sensor wire that he pulls from the main harness somewhere. We haven't used the stock sensor (which I think is built into the front sprocket cover??).

All the gears do have a different reading...so you may try finding the wire in the harness before the stock sensor. From memory, I believe it is green with a black band....but you may want to verify that with someone before you start getting crazy.

Matt Conrad
Phoenix Race Works, LLC

[Mike Devins]

The output voltages from the sensor are as follows:

1st gear = 1.782v
2nd gear = 2.242v
3rd gear = 2.960v
4th gear = 3.630v
5th gear = 4.310v
6th gear = 4.660v
Neutral = 5.000v

This was from some old info I had on the 2002 gxsr that I had a few years ago. You may have a sensor going bad.

[Nicholas Belling]

From my experience on an 07/08 gsxr is that it is not possible to get reliable gear position data.. the reason is that the voltage fluctuates under running conditions vs engine off and running the pot through its gears.. most data acq. systems want a voltage and then a gear or value for it.. but the fact is there is a voltage range for each gear.. hence why in the bike world you hear gear indicators being sluggish and slow to respond because the voltage sometimes can be close to another gears voltage so it has to smart figure out based on voltage currently what it should be.

I do all mine via gear based calculations and it has been 99% accurate using CDS.. but now after spending quite sometime with a fully electronic smart shifter setup for the car the solution for the gear position is apparently to put an aftermarket petonimeter in the motor that has guarenteed predifined voltages coming out based on a 12v independent signal going into the pot...

[martyb]

I'm with Nicolas on this one. We have tried calibrating the AIM dash with the 07 engine not running, and the values change when you start the engine. We then tried calibrating the dash with the engine running, but found we could get different values at different engine RPM's. The best compromise seemed to give us 2nd through 5th fairly reliably.

Marty

[ghickman]

Hi All
Thanks for the input on resolving the gear position pot. problem.

I can see now that this voltage seems to be somewhat unreliable depending on if the engines running or not.

We had George Dean do our harness and he did leave a wire out for Neutral position. We put an LED on the dash using that signal.

I think I'll take Nicholas Bellings advice and use the calculated gear postion using RPM vs WHEEL SPEED, seems that he's been using this with good results.

I'll let everyone know how this worked out.

Thanks again for all the input.....I'm Look forward to seeing all of you at the ARRC RACE in November.

Gary

[Sean Maisey]

Nicholas,

Can you recommend a 3rd party POT for the Suzuki geaer shift?

I have always had the same problem with the stock setup. (I really think the gear position display is fairly useless anyway). But, it would be nice to NOT see incorrect info - that can be distracting.

On the other hand if I give up on the gear reading, I can use that channel for another sensor of some sort???

Sean

[carnut169]

I would recommend a Gi Pro Gear position sensor/ tre. Get's rid of the timing retard in the 1st 3 gears + has a super bright gear position display. Works great.

Easily seen in the pic on the left...

[RussMcB]

I would recommend a Gi Pro Gear position sensor/ tre. Get's rid of the timing retard in the 1st 3 gears + has a super bright gear position display. Works great.

Easily seen in the pic on the left...

I tend to agree. I have both the AIM and GI Pro. My AIM uses speed and RPM to determine what gear the car is in. It works fine, but the display is so dim I could not read the AIM gear display at the last race (Barber, sunny). Maybe a shroud will help. I recently raised both my AIM and GI Pro so they would be more in my line of sight. I'm not sure if that caused the dimness or glare problem. I think it did, because I could read the AIM gear position before, but it was too low (on the steering wheel hub).

The GI Pro plugs into the bike engine's harness and seems to do a pretty good job of determining the gears 95% of the time, and it is easily readable.

I'm hoping that when I get more seat time with my FB and familiar with it at specific tracks, the gear indicator will become unimportant.